Stents for transluminal implantation (also called "expandable intraluminal graft") have been developed these last few years. They are metallic supports which are inserted into a part of the human body, (such as the bile ducts, the urinary system, the digestive tube, . . . ) and notably by percutaneous route, inside the blood vessels, generally the arteries (in which case they are called vascular stents). The supports are adapted to expand radially. They are inserted while they have a first diameter (d.sub.1) and implanted, in the desired area, for example inside the vessel, and expanded in situ, until they reach a second diameter (d.sub.2 :d.sub.2 &gt;d.sub.1). An angioplasty balloon, associated to a catheter, can be used to expand them radially.
Several types of stents are known, and in particular so-called "flexible" stents, such as those described in Patent Applications FR-A-2 525 896 and EP-A-0 183 372 and so-called "rigid" stents, such as those described in Patents U.S. Pat. Nos. 4,739,762 and 4,776,337 or in Patent Applications EP-A-0 221 570 and EP-A-0 364 787.